title: Enhanced angiogenesis in porous collagen-chitosan scaffolds loaded with angiogenin.
abstract: Artificial dermis lacks a vascular network, and angiogenesis is slow in vivo. Controlled delivery of angiogenin (ANG), a potent inducer of angiogenesis, should promote angiogenesis in artificial dermis. In this study, a porous collagen-chitosan scaffold was fabricated and heparinized using N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) and N-hydroxysuccinimide (NHS) with a freeze-drying method. Using radioiodine labeling, the effect of heparin on the binding of ANG to the scaffold was studied. The release of ANG from the heparinized scaffold was investigated using a radioiodine labeling method or an enzyme-linked immunosorbent assay method. In vivo angiogenesis of the scaffold was studied for 28 days. All scaffolds possess three-dimensional porous structures, and their mean pore sizes increase upon EDC-NHS cross-linking. The binding of ANG to the scaffold showed a linear correlation with ANG concentration. With ANG concentrations of 160 ng/mL, the binding of ANG to the heparinized scaffold was 36.5%. In vitro, ANG was released from the heparinized scaffold in a controlled manner. The presence of ANG enhanced the angiogenesis of the heparinized scaffold after subcutaneous implantation into rabbits. The results of this study indicate that a porous collagen-chitosan scaffold loaded with ANG may be valuable in the development of artificial dermis requiring enhanced angiogenesis.
authors.affiliation: Department of Burn, Second Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, China.
authors.forename: Haifei
authors.initials: H
authors.lastname: Shi
authors.forename: Chunmao
authors.initials: C
authors.lastname: Han
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Mao
authors.forename: Lie
authors.initials: L
authors.lastname: Ma
authors.forename: Changyou
authors.initials: C
authors.lastname: Gao
mesh_terms: D000818:Animals; D048271:Chitosan / Q000737:chemistry* / Q000378:metabolism; D003094:Collagen / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008855:Microscopy, Electron, Scanning; D018919:Neovascularization, Physiologic / Q000187:drug effects; D016062:Porosity; D011485:Protein Binding; D011817:Rabbits; D012259:Ribonuclease, Pancreatic / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D017768:Skin, Artificial; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D003094:Collagen; D048271:Chitosan; C046366:angiogenin; D012259:Ribonuclease, Pancreatic